Preparation of dye-receptive poly-



United States Patent 3,126,246 PREPARATION OF DYE-RECEPTIVE POLY- GLEFDI FIBERS Vittorio Cappuccio and Ubaldo Riboni, Terni, Italy, as-

signors to Montecatini Soeieta Generale per llndustria Miner-aria e Chimica, a corporation of Italy No Drawing. Filed Jan. 14, 1960, Ser. No. 2,333

Claims priority, application Italy Jan. 15, 1959 8 Claims. (6]. 8115.5)

The present invention relates to the production of dyereceptive fibres of crystalline polyolefins, particularly polypropylene.

It is believed to be well appreciated by those skilled in the art, that polyolefin fibres, due to their inherent hydrophobicity and inertness, are extremely diificult to dye. In order to solve this problem, several methods have been proposed, such as:

(l) Mixing the polyolefins with other polymers.The polyolefins are mixed with other resins (epoxy resins, polyamides, polyimines, polyesters and the like) capable of rendering the fibres dyeable. The mixtures are then spun according to the usual spinning techniques.

(2) Grafting of reactive monomers onto the fibres. The polyolefin fibres, in the presence of reactive monomers, are treated with agents which catalyze the graft polymerization of said monomers onto said fibres. As reactive monomers, vinyl-type monomers (acrylonitrile, styrene, vinyl esters), vinylpyridines, isopropylpyridines, nitrogen-containing monomers in general and monomers having an acid character are used.

(3) Mixing of polyolefins with various monomers before spinning.The polyolefins are added to vinyl monomers, acid monomers and the like before spinning and the mixes are then subjected to the normal technological operations in the preparation of textile fibres.

(4) Chemical treatments of the fibres.The polyolefin fibres are subjected to sulfonation. The sulfonated fibres are then subjected to an amination treatment.

Unfortunately, none of these proposed processes has been entirely satisfactory from both the technological and economic viewpoints.

The main objects of the present invention, therefore, are to provide a new process for manufacturing improved dye-receptive polyolefin fibres.

Another object is to provide new spinning mixtures of polyolefins in order to permit a lower spinning temperature.

Other objects and advantages of this invention will become apparent on further study of the specification and appended claims.

These objects are obtained by mixing the polyolefin with a halogenated organic compound, spinning this mixture to form fibres and then subjecting the fibres to the action of amine or imine compounds. The final fibres are found to be particularly receptive to acid dyes.

The criterion for selecting the halogenated organic compound is that it must be capable of reacting with amines or imines. Naturally it is desirable that a significant yield of reaction product is obtained, but it must be appreciated that even a very small yield will result in a detectable increase in the dye-receptivity of the fibres. In making a selection of the halogenated compound, it is a simple matter for a chemist to test various compounds by mixing them with boiling amines or imines for up to three hours to determine if a reaction occurs.

Chemical technology being in a constant state of metamorphosis, it is easy to understand that compounds considered economical and useful to-day, can be displaced by the discovery of new processes and/or new products.

As for the present, it has been found that halogenated 3 ,126,246 Patented Mar. 124, 954.-

aliphatic compounds are particularly desirable, and even more particularly, the following:

Dichloroethylene 1,2-dichloropropane 1 ,2,3 -trichloro prop ane Dichlorobutanes Trichlorobutanes Dichloropentanes Trichloropentanes Dichlorohexanes Trichlorohexanes and mixtures of any and all of the above.

As another criterion for these haloderivatives, it is preferable that they have a boiling point above about C. at atmospheric pressure in order to avoid consequential vaporization losses during the spinning operations. Of course, if a certain haloderivative, boiling below about 120 C., is found to be particularly desirable, it may be economically justified to operate the process under pressure in order to raise the boiling point and decrease vaporization losses.

This addition of the halogen derivatives also permits the use of lower melt spinning temperatures than are normally used in the melt spinning of polyolefins alone. These lower melt spinning temperatures are associated with several operating advantages such as, less energy requirements, less hazardous operations, and less degradation of the polymer.

The ratio of polyolefin to halogenated compound is from about 99:1 to 5:1, in parts by weight.

The amination of the fibres obtained from mixtures of a polyolefin with a halocompound is preferably carried out by treating the fibres with boiling aqueous amine or imine solutions, for times, varying from a few seconds to 2 or 3 hours, depending on the reactivity of the amine used. The use of aqueous amine solutions at high temperatures is advantageous since water forms, in general, azeotropic mixtures (which can be removed more easily) with the halogenated compounds; these solutions, due to the temperature, cause a swelling of the fibre and therefore a thorough amination inside the same fibre.

The selection of the amine or imine is, like the selection of the halogenated compound, accomplished by a simple test, and additionally, is subject to the same fluctuations from technological change. At present the following imines and amines have been found to be particularly suitable:

Ethylendiamine Trimethylendiamine Diethylentriamine Tetraethylenpentamine Ethylenimine Polyethylenirnine and mixtures of any and all of the above.

The concentration of amine or imine in solution can naturally vary considerably, the higher the concentration, the faster the rate of reaction. The reaction times and temperatures can also vary, the longer the time, the more complete the reaction, and the higher the temperature, the faster the rate. It is to be appreciated that a chemist can work at a sufficient concentration of amine or imine for a sufi'icient time at a sutficient temperature to obtain at least a partial reaction to improve dye-receptive properties. It has been found, however, that for preferred practicable operations, in general, the concentration of amine can vary from 5% to 65%, the temperature can vary from 50 to 120, and the time can vary from 30 seconds to 3 hours.

In order to explain this invention with more lucidity,

reference is made to the following nonlimitative specific embodiments of the present invention.

Example I Using a polypropylene having the following characteristics:

Intrinsic viscosity 1.23

Ash content, percent 0.2

Residue of the heptane extraction (isotactic polymer) percent 85.6

a mix of 9 kg. polypropylene and 1 kg. dichloroethane is prepared at room temperature in an apparatus of the Werner type.

The mix is spun in a melt spinning apparatus with a spinning head temperature of 170 C. The fibres are stretched with a ratio of 1:5 at 120 C. and are then cut; the staple is introduced into an aqueous ethylendiamine solution solution) with a fibre/bath ratio of 1:30; after boiling for 30 minutes the staple is Washed and dried. The fibres dyed with acid dyes present colors having a good intensity and fastness.

Example II Using polypropylene having the following characteristics:

Intrinsic viscosity [1;], 124. Residue of the heptane extraction, 96.2% in parts by weight. Ash content, 0.03% in parts by weight.

Example III Using a polypropylene having the following characteristics:

Intrinsic viscosity 1.32 Residue of the heptane extraction, percent 94.3 Ash content, percent 0.06

a mix of 8.5 kg. polypropylene with 1.5 kg. 1,2,3-trichloropropane is prepared at room temperature. This mix is spun at a spinning head temperature of 170 C. The fibres are then stretched with a ratio of 1:5 at 120 C. and, in the form of skeins, are heated to 95 C. for 1 hour in a 25% aqueous polyethylenirnine solution, with a fibre/ bath ratio of 1:20.

The fibres subjected to dyeing with the following acid dyes:

Solid yellow 2 G Novamine red B Alizarine blue ACF the resulting fibres exhibit intense and fast colors.

Example IV Using a polypropylene having the following characteristics:

Intrinsic viscosity [1]] 1.14 Residue of the heptane extraction, percent 95.4 Ash content, percent 0.6

a mix of 9 kg. polypropylene and 1 kg. 1,2-dichloropropane is prepared at room temperature. The mix is spun at a spinning head temperature of 160 C. The fibres obtained are passed (with a residence time of 10 minutes) through a vessel containing a 50% aqueous tetraethylenpentamine solution at C. They are then stretched with a ratio of 1:5 at C.

The fibres are intensely dyed, with fast colors using the acid dyes.

Example V Using a polypropylene having the following characteristics:

Intrinsic viscosity [7;] 1.04 Residue from the heptane extracting, percent 95.6 Ash content, percent 0.066

a mix of 8 kg. polypropylene and 2 kg. 1,4-dichlorobutane is prepared at room temperature. This mix is spun at a spinning head temperature of C. The fibers are passed (residence .time of 10 minutes) through a vessel containing a 50% aqueous ethylendiamine solution at 95 C. They are then stretched with a ratio of 1:5 at 120 C. The fibres thus obtained are dyed with acid dyes obtaining intense and fast colors.

As can be seen from the examples, the fibre can be stretched either prior or subsequent to the amination step.

Whereas this invention is particularly suitable for crystalline polypropylene such as those having a prevailingly isotactic content, i.e. over 50%, it is also useful with other fibre forming polyolefins such as the crystalline polyolefins, particularly the prevailingly isotactic ones. For a detailed description and process for making these prevailingly isotactic polymers, reference is made to the pending applications of Natta et al., Serial Numbers 514,- 097, 514,098, and 514,099, filed June 8, 1955, and 550,164 filed November 30, 1955. For a publication, see the Journal of Polymer Science, April 1955, vol. XIV, Issue No. 82, pp. 143-154.

With reference to the foregoing examples, they can be repeated successfully using as the halogenated compound, the fiuoro, bromo and iodo compounds instead of the chlorinated aliphatic compounds. Furthermore, following tl e process outlined in the examples, other polyolefins found to be most suitable, are polyethylene, polybutene and mixtures of these polymers.

It is understood that the inventors intend to claim, as part of their invention, any variation, substitution and changes that lie within the scope of the invention and the hereinafter appended claims and intend to include within the scope of said claims such changes as may be apparent to those skilled in the art in the practice of the principles of this invention and within the scope as set forth in the hereinabove-stated specification.

What is claimed is:

1. A process for preparing dye-receptive fibers of polyolefin fibers of polypropylene consisting prevailingly of isotactic macromolecules comprising the steps of: mixing said polypropylene with a halogenated compound in a ratio from about 99:1 to 5:1, in parts by weight, said halogenated compound being selected from the group consisting of: dichloroethylene, 1,2-dichloropropane, 1,2,3-trichloropropane, dichlorobutanes, trichlorobutanes, dichloropentanes, trichloropentanes, dichlorohexanes and trichlorohexanes, and mixtures thereof; extruding said mixture at a temperature between about 155 C. and C. to obtain fibers; treating said fibers for a time varying from about 30 seconds to about 3 hours, and at a temperature of from 50 C. to 120 C. with an aqueous solution of from about 5% to about 65% of a nitrogen-containing compound selected from the group consisting of: ethylendiamine, trimethylendiamine, diethylentriamine, tetraethylenpentamine, ethylenimine and polyethylenimine, and mixtures thereof; whereby dye-receptive properties of the resulting fiber are enhanced.

2. The fiber product as obtained by the process of claim 1.

3. The process of claim 1 characterized by the additional step of dyeing the fibers.

4. The fiber product as obtained by the process of claim 3.

5. A novel spinning composition permitting lower spinning temperatures and a thorough penetration of chemicals used to alter fiber properties in the formed fiber, comprising polypropylene consisting prevailing of isotactic macromolecules and a halogenated compound in a ratio of about 99:1 to 5:1, in parts by Weight, said halogenated compound being selected from the group consisting of: dichloroethylene, 1,2-dichloropropane, 1,2,3-trichloropropane, dichlorobutanes, trichlorobutanes, dichloropentanes, trichloropentanes, dichlorohexanes, and trichlorohexanes, and mixtures thereof.

6. A process for preparing dye-receptive fibers of polypropylene consisting prevailingly of isotactic macromolecules comprising the steps of: mixing said polypropylene with a halogenated compound in a ratio from about 99:1 to 5:1, in parts by weight, said halogenated compound being a halogenated aliphatic compound having from about 2 to about 6 carbon atoms; extruding said mixture at a temperature of from about 155 C. to about 170 C. to obtain fibers; treating said fibers for a time varying between about 30 seconds and 3 hours, and at a temperature of from about 50 C. to 120 C., With an aqueous solution of from about 5% to about 65% of a nitrogen-containing compound selected from the group consisting of: ethylendiamine, trirnethylendiamine, diethylentriamine, tetraethylenpentamine, ethylenimine and polyethylenimine, and mixtures thereof; whereby dyereceptive properties of the resulting fiber are enhanced.

7. A process for preparing dye-receptive fibers of polypropylene consisting prevailingly of isotactic macromolecules comprising the steps of: mixing said polypropylene with a halogenated compound in a ratio from about 99:1 to 5:1, in parts by weight, said halogenated compound being selected from the group consisting of: dichloroethylene, 1,2-dichloropropane, 1,2,3-trichloropropane, dichlorobutanes, trichlorobutanes, dichloropentanes, trichloropentanes, dichlorohexanes and trichlorohexanes,

and mixtures thereof; extruding said mixture at a temperature of from about 155 C. to about 170 C. to obtain fibers; treating said fibers for a time varying between about 30 seconds and 3 hours, and at a temperature between about C. and C., with an aqueous solution of from about 5% to about 65% of a nitrogencontaining compound selected from the group consist ing of an amine having from about 2 to about 8 carbon atoms and about 2 to about 5 amino groups, and ethylenimines, and mixtures thereof; whereby dye-receptive properties of the resulting fiber are enhanced.

8. A process for preparing dye-receptive fibers of polypropylene consisting prevailingly of isotactic macromolecules comprising the steps of: mixing said polypropylene with a halogenated compound in a ratio from about 99:1 to 5:1, in parts by weight, said halogenated compound being a halogenated aliphatic compound having from about 2 to about 6 carbon atoms; extruding said mixture at a temperature of from about C. to about C. to obtain fibers; treating said fibers for a time varying from about 30 seconds to 3 hours, and at a temperature between about 50 C. and 120 C., with an aqueous solution of from about 5% to about 65 of a nitrogen-containing compound selected from the group consisting of an amine having from about 2 to about 8 carbon atoms and about 2 to about 5 amino groups, and ethylenimines, and mixtures thereof; whereby dye-receptive properties of the resulting fiber are enhanced.

References Cited in the file of this patent UNITED STATES PATENTS 2,261,294 Schlack Nov. 4, 1941 2,829,118 Wehr Apr. 1, 1958 2,979,774 Rusingnolo Apr. 18, 1961 2,980,964 Dilke Apr. 25, 1961 FOREIGN PATENTS 682,175 Britain Nov. 5, 1952 

1. A PROCESS FOR PREPARING DYE-RECEPTIVE FIBERS OF POLYOLEFIN FIBERS OF POLYPROPYLENE CONSISTING PREVAILINGLY OF ISOTACTIC MACROMOLECULES COMPRISING THE STEPS OF: MIXING SAID POLYPROPYLENE WITH A HALOGENATED COMPOUND IN A RATION FROM ABOUT 99:1 TO 5:1, IN PARTS BY WEIGHT, SAID HALOGENATED COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF: DICHLOROETHYLENE, 1,2-DICHLOROPROPANE 1,2,3-TRICHLOROPROPANE, DICHLOROBUTANES, TRICHLOROBUTANES, DICHLOROPENTANES, TRICHLOROPENTANES, DICHLOROHEXANES AND TRICHLOROHEXANES, AND MIXTURES THEREOF; EXTRUDING SAID MIXTURE AT A TEMPERATURE BETWEEN ABOUT 155*C. AND 170* C. TO BOTAIN FIBERS; TREATING SAID FIBERS FOR A TIME VARYING FROM ABOUT 30 SECONDS TO ABOUT 3 HOURS, AND AT A TEMPERATURE OF FROM 50*C. TO 120*C. WITH AN AQUEOUS SOLUTION OF FROM ABOUT 5% TO ABOUT 65% OF A NITROGEN-CONTAINING COMPOUND SELECTED FROM THE GROUP CONSISTING OF: ETHYLENDIAMINE, TRIMETHYLENDIAMINE, DIETHYLENTRIAMINE, TETRAETHYLEPENTAMINE, ETHYLENIMINE AND POLYETHYLENIMINE, AND MIXTURES THEREOF; WHEREBY DYE-RECEPTIVE PROPERTIES OF THE RESULTING FIBER ARE ENCHANCED. 